Subterranean antenna



March 10, 1931. I w c 1,795,534

SUBTERRANEAN ANTENNA Filed Nov. 3, 1928 .r jv Mr Patented Mar. 10, 1931 UNITED STATES PATENT OFFICE ROY M. WYRICK, OF LOUISVILLE, KENTUCKY, ASSIGNOR OF ONE-HALF TO LYNN VAN ARSDALE AND ONE-HALF T0 MILTON E. WALDROP, BOTH 0F LEXINGTON,

KENTUCKY SUBTERRANEAN ANTENNA Application filed November 3, 1928.

This invention relates to antennae for use with radio receiving apparatus and more particularly to the construction of a subterranean antenna.

An important object of the invention is to provide in a device of this character a construction such that the antenna proper is shielded and, at the same time, a construc tion provided preventing corrosion of the antenna. It has long been known that subterranean antennae have certain advantages over the ordinary type, the principal advantage noted being that such antennae are considerably freer from interference resulting from static discharges than the ordinary aerial. They are, however, subject to corrosion, particularly when the antenna is disposed in certain types of soils and in locations where changing temperatures cause a tendency to sweating of the metal forming the antenna. An important object of this invention is to produce an antenna which may be employed in any subterranean location and which is fully and completely shielded and yet is unafiected by changing conditions.

A still further object of the invention is to produce a device of this character which may be very readily and cheaply manufactured.

A still further object of the invention is the provision of a device of this character which will act both as an antenna and ground.

These and other objects I attain by the construction shown in the accompanying drawing, wherein for the purpose of illustration is shown a preferred embodiment of my invention and wherein Figure 1 is a vertical sectional view through a subterranean antenna constructed in accordance with my invention, the connections to a receiving set being diagrammatically illustrated Figure 2 is a transverse sectional view on the line 2-2 of Figure 1.

Referring now more particularly to the drawing, the numeral 10 generally designates Serial No. 316,980.

a cylindrical container having its opposite ends closed and its upper end provided with a central opening 11. Within this container is arranged a tube or collector 12 in the form of a metallic body preferably connected with 5;

12, while the armor 15 thereof is soldered or otherwise secured to the upper wall of the casing about the edges of the opening to complete the seal thereof. This container is evacuated, being preferably provided with a check-valved outlet 16 to assist in its evacuation.

A complete subterranean antenna of this clutractcr may be constructed with an. overall length of eighteen inches and need not be buried in the ground for any great depth, a shallow hole approximately two feet deep sufiicing for its reception. The wire 14 con nected to the antenna receiving binding post of the receiving apparatus, while the shield or armor 15 of the cable may be connected to the ground receiving binding post of the receiving apparatus.

It has been found that by evacuating the container, sweating of the body 12 and corn sequent short-circuiting of this body to the cylindrical casing is eliminated. and it has been further found that the etlioiency in re ception is increased by this evacuation approximately twenty per cent. Receiving apparatus employing an antenna constructed in this manner have been found. to be very free from interference and to be highly selective. In construction, the casing 10 is preferably formed of copper and the inner body 12 is preferably in the form of an aluminum cylinder.

The construction hereinbefor-c set forth being capable of a certain range of change and modification, I do not limit myself thereto except as hereinafter claimed.

I claim A subterranean antenna comprising an evacuated metallic container, a collector Within and space-insulated from the Walls of the container, an insulated lead Wire electrically connected to the collecting body and having insulated passage through the Wall of the container, and a condenser connecting said container and collecting body.

In testimony whereof I hereunto afiix my signature.

ROY H,- WYRICK. 

